SDC1 and Miyoshi myopathy: Though heterogenous, since the average in vivo activity of glutamine anaplerosis into the TCA cycle was different between CD138+ malignant plasma cells from MM patients and their paired CD138- bone marrow mononuclear cells, we assessed the absolute quantification of the concentrations of these TCA cycle intermediates in the bone marrow and peripheral blood plasma of these MM patients and compared them to those from the MGUS patients.